Hydropower, also known as hydraulic power or water power, is one of the many different sources of renewable energy, offering many advantages as opposed to the other similar renewable sources. The energy from this source comes from the harnessed energy or force generated by moving water. Like solar and geothermal energy, the energy from hydropower is not depleted in the process of energy production.Hydropower has many uses. It was previously used for irrigation and machine & mill operations. In fact, it was used in India and Rome in their watermills and water wheels for hundreds of years, as well as in Britain’s metal ore extractions. Today, hydropower is primarily used to generate electricity. It does this in a very efficient manner, as turbines are able to convert more than ninety percent of this renewable energy source into electricity. Also, because it uses water, it is not detrimental to the environment. There are no toxic by-products produced, and no air pollution in the process of energy generation. Furthermore, it has a role in the reduction of greenhouse gas emissions, and is a reliable energy source. This ability to handle seasonal high peak loads is an important attribute of hydropower. In times when there is a low demand for hydroelectric energy, the dam stores more water, thereby producing more flow once it releases, when demands are high again. Aside from electricity production, hydropower projects also serve to control floods, provide water supply to the community and create recreational opportunities.
Hydroelectric energy is used for the electricity generated from large-scale dams. According to the U.S. Department of Energy, hydropower represented 7.1 percent of the sources of energy in 2006. Some states, like Washington, Oregon, and Idaho use it as their main energy source. Hydroelectricity is already a large source of energy not just in the U.S. but also in Canada and Brazil, and there are still many areas in Latin America, Central Africa, China and India that can potentially yield abundant sources of this particular renewable energy. The largest and most notorious hydroelectric dam in the world is the Three Gorges Dam on Yangtze River.
While hydroelectric energy has many advantages, it also has its downsides. It may lead to loss of habitat for wildlife, changes in stream water quality, and even the displacement of local populations due to the large areas used for hydropower projects. Aside from hydroelectric energy, there are other forms of energy generated from hydropower. This includes tidal power, tidal stream power, and wave power. While tidal power captures energy in a horizontal direction as occurs in bays or sanctuaries, tidal stream powers captures in a vertical direction. Wave power refers to energy captured in ocean surface waves.